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Summary of 2009 Fish Population Minnesota Department of Natural Resources 
Lake Vermilion is part of the statewide Large
Lake Program, an intensive fisheries management
program on the 10 largest lakes in Minnesota. The
Large Lake Program includes annual population
assessments, annual water quality monitoring, and
regularly scheduled creel surveys. A variety of
sampling gear is used during population assessments
to collect the various fish species and life
stages. These gear types include gill nets, trap nets,
beach seines, and an electrofishing boat. Sampling for each
gear type is conducted at the same time and place each
year in order to determine population trends for the
major species. Data is also collected on length, weight,
age, and growth for each of the major species.
The walleye gill net catch in 2009 was 13.4 fish/net; slightly below the historical average for Lake Vermilion. It was the second consecutive year walleye gill net catches were below average. Lower than average walleye catches in recent years was due primarily to poor reproduction in 2004 and 2005. Gillnetted walleye had a mean length of 14.0 inches, well above the historical average. The large average size was due to high numbers of 17-20 inch walleye in the catch from strong year classes produced in 2002 and 2003. Most of these larger walleye were sampled on West Vermilion. The gill net catch of 14-16 inch walleye was below average for those size classes, reflecting poor reproduction in 2004 and 2005. The walleye gill net catch was dominated by age 2 fish (2007 year class) and age 3 fish (2006 year class), which comprised 28.7% and 31.3% of the catch, respectively. Both the 2006 and 2007 year classes appear to be moderately strong. Strong year classes of walleye were also produced in 2002 and 2003, while poor year classes were produced in 2004 and 2005. One year of netting indicates the 2008 year class will also be weaker than average. A special walleye regulation went into effect on Lake Vermilion in 2006; a 17-26 inch protected slot with one fish allowed over 26 inches, and a four fish bag limit. A more restrictive regulation was adopted because of increased fishing pressure and walleye harvest. The regulation will help keep harvest at a safe level while allowing anglers to keep eating sized walleye. The gill net catch of northern pike was 1.1 fish! net; slightly above the historical average. Gill net catches of northern pike have historically been fairly stable at a relatively low level. The mean length of northern pike sampled by gill nets was 27.2 inches, slightly above the historical average, although the sample size was only 22 fish. Reproduction of northern pike is usually fairly consistent from year to year, although it appears a relatively poor year class was produced in 2003. A special regulation for northern pike went into effect on Lake Vermilion in 2003; a 24-36 inch protected slot, with one fish allowed over 36 inches. This regulation is part of a statewide initiative to improve the size structure of pike populations in a number of lakes across the state. The gill net catch of yellow perch was 17.0 fish/net; well below the historical average. It was the third consecutive year of low perch catches. Low perch catches in recent years were due primarily to poor reproduction in 2004 and 2005. Gillnetted perch had a mean length of 7,4 inches, which is near the historical average. The perch catch was dominated by age 3 fish (2006 year class), which comprised 50.9% of the catch. Although the 2006 year class dominated the perch catch, it is only average in strength. Poor year classes of perch were produced in 2004 and 2005. The last strong year class of perch was produced in 2002. The trap net catch of bluegill was 39.0 fish/net; well above the historical average. The bluegill catch was much higher on West Vermilion than East Vermilion, reflecting higher bluegill abundance in that lake basin. Trapnetted bluegill had a mean length of 5.8 inches, slightly below the historical average. Over 80% of the bluegill catch was less than 7 inches long, reflecting strong young year classes in the population. The bluegill trap net catch was dominated by age 4 fish (2005 year class), which comprised 42.6% of the catch. Strong year classes of bluegill were produced in 2005 and 2006, while a poor year class was produced in 2004. The black crappie trap net catch was 1.9 fish/net; slightly above the historical average. Crappie numbers have historically been relatively low on Lake Vermilion, although some areas of West Vermilion have higher numbers of fish. Trapnetted crappie had a mean length of 8.5 inches, slightly above the historical average. The catch of 8-9 inch crappie was well above average, reflecting the presence of a strong 2005 year class. The crappie catch was dominated by age 3 fish (2006 year class) and age 4 fish (2005 year class), which comprised 44.6% and 50.0% of the catch, respectively. Strong year classes of crappie were produced in 2005 and 2006, while a poor year class was produced in 2004. An electrofishing boat is used as the standard sampling gear for smallmouth bass because they are not often caught in standard assessment nets. The smallmouth bass electrofishing catch in 2009 was 37.3 fish/hour, which is near the historical average. Smallmouth bass sampled by electrofishing had a mean length of 10.6 inches, well above the historical average. High numbers of 13-15 inch bass were sampled from strong year classes produced in 2002 and 2003. The bass catch was dominated by age 3 fish (2006 year class) and age 4 fish (2005 year class), which together comprised 63.4% of the total catch. Both the 2005 and 2006 year classes are much stronger than average. A poor year class was produced in 2004. An electrofishing boat is used to sample young-of-the-year walleye in the fall to monitor reproductive success for the year. The fall electrofishing catch of young-of-the-year walleye was 52.9 fish/hour; the lowest catch since sampling began in 1988. The mean length of young-of-the-year walleye sampled by electrofishing was 4.6 inches, well below the historical average. Growth of young-of-the-year walleye has proven to be a useful indicator of eventual year class strength. Past sampling has shown that large, fast growing young-of-the-year walleye generally produce strong year classes, while small slow growing fish produce poor year classes. Taken together, the 2009 electrofishing catch and growth rate indicate the 2009 year class will likely be very poor. Unusually cool spring and summer weather in 2009 probably had a negative effect on reproductive success of walleye and many other fish species. Muskie population assessments have been done once every four years on Lake Vermilion, although future assessments will be done once every six years. East Vermilion and West Vermilion are done in different years due to the large size of the lake. Trap net catches of muskie have been gradually increasing since the first assessments were done in 1993 and 1994. The number of large fish has also been increasing. Over 15% of the muskie sampled in 2005 and 2006 were over 50 inches long. The largest muskie sampled during the 2005-2006 assessments was 54.7 inches long. The next assessments are scheduled for 2010 and 2011. I encourage anyone who has questions about fish populations on Lake Vermilion to contact me or stop by our office for a visit. The DNR office is located just west of Tower on highway 169. duane.williams@dnr.state.mn.us Joe Geis, Area Fisheries Supervisor, 218-753-2580, ext. 222 joe.geis@dnr.state.mn.us MN Dept. Of Natural Resources Division of Fisheries 650 Hwy. 169 Tower, MN 55790 |